1 Despite the advent of highly effective prevention tools such as HIV pre-exposure prophylaxis (PrEP), Black men 2 who have sex with men (MSM) continue to have the highest incidence of new HIV diagnoses in the US. The risk 3 of onward HIV transmission is reduced to zero in HIV-positive individuals who are virally suppressed; however, 4 Black MSM are least likely to be engaged in care or to be suppressed. Many Black MSM face multiple stigmas 5 (e.g., racism, homophobia) and rejection from their biological families, but some have found refuge in the House 6 Ball Community (HBC)?a national network of Black LGBT kinship commitments (families) that provide (informal) 7 care giving, affirmation and survival skills-building for its members. Regarding skills-building and HIV prevention, 8 Many Men Many Voices (3MV) is a six-session, group-level behavioral intervention and is the only ?best- 9 evidence? intervention for Black MSM. Family-based interventions have shown HIV prevention efficacy; however, 10 3MV is not a family-based intervention. In 3MV, HIV-negative Black MSM are recruited into artificial group 11 settings with individuals with whom they may have little social relationship. 3MV neither leverages the 12 connections and commitments nor addresses the variability in HIV-status that exists in house ball families. 13 Because Black MSM in the HBC have closer social relationships, 3MV requires adaptation to be more responsive 14 to this social structure and dynamic. Our goal in this clinical trial planning grant is to prepare for a cluster 15 randomized controlled trial (CRCT) to test the effectiveness of the modified 3MV vs. standard of care in reducing 16 new HIV infections and increasing rates of viral suppression among Black MSM in HBC families. Based on our 17 formative work, that MSM social networks predict HIV prevention behaviors and that HBC family cultural norms 18 are primed for communication about HIV prevention and treatment, our central hypothesis is that a modified 3MV 19 intervention incorporating family asset-building will have an amplifying effect on HIV prevention and treatment 20 outcomes. We will investigate this hypothesis with the specific aims: Aim 1: Conduct formative research to 21 identify key modifications to the 3MV intervention manual and implementation protocol. The eight-step ADAPT- 22 ITT model will guide our approach to modifying 3MV into Our Family Our Voices (OFOV), which accommodates 23 the lived experience of HBC families. Aim 2: Conduct a pilot CRCT to determine the feasibility and acceptability 24 of the modified 3MV trial protocol (OFOV) vs. waitlisted standard of care control. We will determine the feasibility/ 25 acceptability of OFOV as well as the CRCT design (n=6 families; 100 individuals) with NYC HBC families. This 26 study will provide necessary data to design and conduct a full-scale CRCT effectiveness trial of OFOV on HIV 27 prevention and care outcomes in Black MSM. The HBC is a large, yet underserved, community within the LGBT 28 community. By precision-tailoring an evidence-based intervention for the HBC, our research to improve HIV 29 testing and care engagement will complement national efforts to End the Epidemic by 2030, especially among 30 Black MSM?the highest priority group for domestic HIV prevention.